Ainsley Iggo FRS (2 August 1924 – 25 March 2012) was a New Zealand born neurophysiologist.

After gaining a BSc and an MSc in electrophysiology and neuroscience at the University of Otago in Dunedin, with a thesis on rumen digestion in sheep,[2] he moved to Aberdeen to join the Rowett Research Institute, an agricultural research facility of the University of Aberdeen.

[3] In 1958 he became the first scientist to demonstrate electrical recordings from individual C fibres, the thinnest of the body's nerves and also defined the function of the various sensory receptors in the skin which detect touch, tickle, heat and pain.

[3] Iggo received a DSc from the University of Edinburgh in 1963 for his thesis, “Mammalian afferent nerve fibres".

[4] In 1973 he was a founder member and later president (1981–84) of the International Association for the Study of Pain (IASP).